Lamination process optimization utilizing neopentyl glycol-modified polyesters

Abstract

Thermoplastic articles made from polyesters modified by neopentyl glycol laminate more quickly than cyclohexanedimethanol-modified versions yet retain the properties that make modified polyesters the material of choice in this market—water-like color and clarity, high impact strength, low lamination temperature and low flammability. For situations where a faster cycle time is not needed, articles laminated with neopentyl glycol-modified polyesters can alternatively be manufactured at lower temperatures.

We claim: 
     
       1. A thermoplastic article obtained by contacting a laminate comprising a first sheet material and a second sheet material with heat and pressure using a heated element which results in the simultaneous bonding of the sheet material;
 wherein the first and second sheet materials are formed from a copolyester having an inherent viscosity of 0.5 to 1.2 dL/g, when measured at 25° C. using 0.50 grams of polymer per 100 mL of a solvent consisting of 60 weight percent phenol and 40 weight percent tetrachloroethane comprising: 
 (i) diacid residues comprising at least 80 mole percent terephthalic acid residues; and 
 (ii) diol residues consisting essentially of ethylene glycol residues and neopentyl glycol residues in a mole ratio of ethylene glycol to neopentyl glycol of from about 38:62 to 88:12, 
 wherein the laminate has an interfacial adhesion at least about 1.5 times greater than a laminate with diol residues consisting essentially of ethylene glycol residues and 1,4-cyclohexanedimethanol residues in a mole ratio of ethylene glycol to 1,4-cyclohexanedimethanol of from about 38:62 to 88:12. 
 
     
     
       2. A thermoplastic article according to  claim 1  wherein the upper and lower sheet materials have a thickness in the range of about 0.38 to about 12.70 mm. 
     
     
       3. A thermoplastic article according to  claim 1  wherein the upper sheet material has a thickness in the range of about 0.38 to 12.70 mm and the copolyester has an inherent viscosity of 0.6 to 0.9 dL/g, when measured at 25° C. using 0.50 grams of polymer per 100 mL of a solvent consisting of 60 weight percent phenol and 40 weight percent tetrachloroethane. 
     
     
       4. A thermoplastic article according to  claim 3  wherein the article includes an abrasion-resistant coating on one or both of the outside surfaces of the article. 
     
     
       5. A thermoplastic article according to  claim 4  wherein the abrasion resistant coating is provided as a film having a thickness in the range of about 0.0025 to 0.381 mm. 
     
     
       6. A thermoplastic article according to  claim 4  wherein the abrasion resistant film is provided as a fluorinated hydrocarbon, poly(perfluoroethylene), or oriented poly(ethylene terephthalate) film having a thickness in the range of about 0.0025 to 0.381 mm. 
     
     
       7. A thermoplastic article according to  claim 4  wherein the abrasion resistant coating is a heat-, ultraviolet- or electron beam-cured material on a film of poly(vinyl chloride), PETG copolyester, poly(ethylene terephthalate), poly(methyl methacrylate) or polycarbonate. 
     
     
       8. A thermoplastic article according to  claim 3  wherein the upper sheet material has a thickness of 1.27 to 6.35 mm. 
     
     
       9. A thermoplastic article according to  claim 7  wherein the abrasion resistant coating is a heat-cured silicone, polyurethane or fluorinated polyurethane or a ultraviolet- or electron beam-cured material selected from modified acrylates containing polyurethane, fluorinated polyurethane, silicone, epoxy, polyester, polyether or caprolactone residues. 
     
     
       10. A thermoplastic article according to  claim 2  wherein the upper sheet material is transparent and the lower sheet material is translucent or opaque. 
     
     
       11. A thermoplastic article according to  claim 1 , wherein at least one of the sheets has a decorative texture or design on its surface. 
     
     
       12. A thermoplastic article according to  claim 1 , further comprising an insert adhered to one of said first sheet material or second sheet material or encapsulated between said first sheet material or second sheet material. 
     
     
       13. A thermoplastic article according to  claim 12 , wherein the insert is selected from the group consisting of films, fabric, metallic wire, rod, bar, mesh, decorative amorphous metallic surfaces, wood, stone, paper, printed images, vegetation, wood, wood chips, grasses, thatch, flowers, flower petals, wheat, grains, natural papers, glass, crushed glass, pebbles, moss, and the like, or at least one electrically energized device comprising light emitting capacitors (LEC's), light emitting diodes (LED's), printed circuit boards or paper that emit light when energized, electrochromic layers, photovoltaics, transmitters, receivers, antennas, electromagnets, electrodes and smart sensors. 
     
     
       14. A thermoplastic article according to  claim 13 , wherein the article is selected from the group consisting of counter tops, table tops, cabinet doors, game boards, toys, panels for shower stalls, hot tubs, marker boards, indoor signs, outdoor signs, vanity tops, flooring, billboard signage, backlit bus advertisement, street furniture, bus shelters, visual merchandizing displays, flooring, ceilings, kiosks, smart sensors, decorative walls, partitions, glazing applications, and skylights.